Oil seal



Julie 13, 1939.

H. C. HILL OIL SEAL Filed Jqly 8, 1957 Y a w W L a, T 1 x w 2 Z K\\N Ll m MW\J&V

' INVENTOR. HENRY .HZLL

Patented June- 13,

UNITED STATES PATENT OFFICE-2c Henry c. niu, Paterson, N. 1., assignor to Wright Aeronautical Corporation, a corporation of New York Application m a. 1937, Serial No. 152,555

' roams." 1(Cl. 285 l) This invention relates to improvements in'oil seals of the type wherein a rotating. shaft member is provided with annular grooves in which are seated ringswhich .bear 'against the cylindrical interior surface ofa bearing member. It is known that seals of this character have been used in the art and, although the simple form of seal may be satisfactory in certain environments, it has been found faulty in structures wherein very-high fluid pressures are imposed on the seal, and wherein rotational speeds are high. Under these conditions, the sealing rings are prone to excessive wear, and the practical life of the rings is, so short as to make the simple organization unsatisfactory. A particular environment to which an improved seal of the character herein disclosed is applicable'is in the oil transfer bearings of an aircraft engine adapthollow, as indicated at It, and acts as an oil conduit delivering oil through a drilling ",through the bushing l2 and through a drilling in the propeller shaft to an oil passage 2| leading to the-intake'of a high pressure pump, not shown. 5 The oil in the conduit I8 is under a moderate degree of pressureot the order of 60 to 100 lbs. per

-- square inch. Oil from the above mentioned high ed for a hydraulically controlled controllable pitch propeller. In such instance, pressures of the order of six hundred pounds per square inch.

must be transferred from a pump to a rotating shaft member without undue loss of pressure or fluid.

- An object of the invention is to provide-a novel Fig. 1 is an axial section through a mechanism embodying the improved oil seal of this inven-! tion; r

' Figs. 2 and'3 are, respectively, exploded views" of-diiferent portions of the sealing elements; and

Fig. 4 is a CIQSSQSGCHOH througha fragment ofone of the: split sealing rings.

Fig. 1 representsaircraft engine wherein -III is aportion of the engine'crankshaft, embraced by a bearing bushing I! on which is formed a propeller shaft, shown in part as ll Surrounding the propeller shaft ll isa sun gear ii mounted on an annular bracket 11 which-is'adapted for attachment to the v enginejcasing,not shown. 'The gear I, along with the flange shown at the right hand end of the propeller shaft II, are parts of the engine 55 reduction gear, not shown. crankshaft I! is rt ofthe mechanism of an r for minimizing any oil leakage.

-to apropeller control mechanism. In'order to conserve the oil pressure and to prevent leakage between the propeller shaft l4 and ,the member 15 I1, an oil sealing organization, designated in its entirety as is utilized. This organization com prises sleeves 26 and 21 arranged in series between the member IT and the propeller shaft, and

. a ring 28 cooperating with the sleeve 21, the latter ring being held in place by a portion 29 of the propeller shaft locking ring. The sleeve 16 includes a pair of ring grooves 30 inwardly disposed relatively to a duct 3| establishing communication between the drillings 20 and, these grooves 30 having seated therein split rings 32 to serve as oil seals. The rings v32 are provided with a plurality of circumferentially spaced through openings 33 establishing communicationbetween the respective flat faces of the rings, and counter 30 bores 34 serve to distribute lubricant accumulating on the ring faces over a substantial area in the ring groove. In operation, oil pressure exists in the duct 3|.which would tend ordinarily to leak toward the right, as shown in Fig. 1, this leakage being prevented by the rings 32. These rings spring outwardly against the herein the member I1 and will, normally,.not rotate. The v oil pressure will press the rings against the right "hand faces of the respective grooves, providing a vsmall clearance at the left hand face of each. ring,

and beneath'each ring. This oil pressure will tend to force the rings outwardly against the bore 'of the member I! to effect sealing at the bore 'face. The holes33 permit of oil to pass from the'left hand side of ach ring to the right hand side thereof to lubricate that right hand face' of each ring which rubsagainst the. right hand groove face, still establishing a seal at this point In the prior art, rings of the type disclosed, but without oil drlllings,were utilized, and it was found that the rings would tend to bind against the groove faces I whereby rapid wear of the ring or groove would result. vShould the ring rotate with the grooved 5 member, rapid wear would occur on the periphery of the ring at its point of engagement with the bore surface. The rings, with oil holes, as above described, have been found to be very effective with moderate oil pressures, and wear is practically negligible over a long period of time. 7

The seals on each side of the high pressure oil duct 36, joining the ducts 22 and 23, comprise a still further improvem'nt, in order to eifectively prevent leakage where the very high pressure makes sealing difiicult. The components of this joint are shown in Fig. '2 wherein the sleeve 21 is provided with rectangularly shaped shoulders on each side of the duct 36, engaging at their re-- spective ends the sleeve 25 and the ring 28. When so assembled, the shoulders provideannular rectangularly proflled grooves on each side of the duct 36 within which are located split sealing rings 38 having through oil passages spaced therearound as in the case of the rings 32. This ring is on the pressure side of the joint and rests against a solid ring on the low pressure side of the joint, the solid ring 4 0 in turn bearing upon the respective end faces of the sleeve 26 and ring 28. The solid ring, in operation, will have some clearance with respect to the bore surface of the member i1, and will tend vto rotate with the respective elements 26 and 28. The rings 38, on

the contrary, will tend to remain stationary, due

to their spring engagement with the boresurface of the member i1, and. the sealing eflect-of the ring a with the ring 40 will be substantially identical with that ut' in connection with Fig. 3. The benefit aiforded by the solid ring 40 is as follows: In machining annular grooves in a member, it is very difficult to have the side faces of said grooves perfectly smooth and coplanar throughout their periphery, which characteristics are essential for producing an effective joint which will be tight against high pressure. The separate rings ll may readily be finished .to a high polish and to nearly absolute planeness, and thus afford a perfect sealing joint in cooperation with the rings 3! with respect to whichthey rotate.

Thus, it'will be seen that thabove description provides two essentially similar forms of sealing joints, both utilizing the drilled split rings, where-- by lubrication may be provided against the working faces thereof. That joint which uses the perfectly formed solid ring 40 as a bearing medium is adapted for use under conditions where very high hydraulic pressures are imposed upon thejoint, whereas said solid ring may be eliminated if the hydraulic pressures imposed on the joint are not so severe. However, the solid ring 40 may,

likewise be used in connection with the -low pres- 'sure joint' if so desired. When the Joint is orin the appendedclaims to cover all such modiflcations and-changes.

What is claimed is:

dial drillings therein adapted for fluid transfer therebetweema sleeve between the shaft and cylinder 'flxedto the shaft havinga radially drilled '1. In a shaftand cylinder assembly having raannular portion for fluid transfer between said drillings, annular grooves in the sleeve at each end of said annular portion, split spring rings seated in said grooves and non-rotatably bearing on the cylinder, said rings being axially slidable in said cylinder under the influence of fluid pressure in said annular portion to abut the groove sides for relatively rotatable sealing contact therewith, said rings having drillings connecting the end faces thereof for transferring fluid from the non-sealing faces for lubrication of the latter.

2. In a shaft and cylinder assembly having radial drillings therein adapted for fluid transfer therebetween, a sleeve between the shaft and cylinder fixed to the shaft having a radially drilled annular portion for fluid transfer between said drillings, annular grooves in the sleeve at eachv end of said annular portion, split spring rings seated 'insaid grooves and non-rotatably bearing 'on the cylinder, solid rings in said grooves on the side of respective split rings most remote from said radial drillings, saidsplit and solid rings being respectively non-rotatable and rotatable with the sleeve and being axially movable in said cylinder under the influence of fluid pressure in said annular portion, .the solid rings abutting and rogagement with the solid ring face for lubrication thereof. 4

3. In a shaft sealing assembly, a housing having a cylindrical bore and a fluid transfer opening intermediate the bore ends, a shaft member within the bore including a fluid transfer opening in substantial alinement with the housing opening, said shaft member having an annular groov on each side of the transfer opening, and a. split, spring ring seated in each groove, non-rotatably' engaging the bore during shaft rotation due to the spring of the ring, said ring beingaxially slidable in the bore and hearing at one side face on that groove side which is most remote from the transfer opening,'whereby to seal the shaft member with respect to the bore, .said rings having drillings connecting respective side faces thereof for transferring fluid from the non-sealing to the sealing faces for lubrication of the latter.

' 4. In a shaft sealing assembly, a housing having a cylindrical bore and a'fluid transfer opening intermediate the bore ends, a shaft member within the bore including a fluid transfer opening in substantial alinement with the housing opening, said shaft member having an annular groove on each side of the transfer opening, a solid ring in each groove bearing 'at its face most remote from the transfer opening'upon the most remote groove face, and a split spring ring seated in each groove between the solid ring and the transfer opening and non-rotatablyengaging the bore, said spring ring being axially movable in the bore and bearing at one side face on the solid ring side nearest to the transfer opening, whereby to seal the shaft member within the bore, said spring rings having drillings connecting respective side faces for transferring fluid from the non-sealing to the sealing faces thereof for lubrication besnring ring. Y C I tween the adjacent, faces of the solid ring and I 

